Robbery alarm system



Jan. 24, 1967 1.. BROUSSEAU ETAL ROBBERY ALARM SYSTEM Filed Oct. 12, 1964 //vv/vr0/?5 lac/en BROI/SSEAU Jean-1.. BROUSSEAL/ Arromvns United States Patent 3,300,770 ROBBERY ALARM SYSTEM Lucien Brousseau and Jean-Luc Brousseau, both of 336 3rd Ave. W., Orsainville, Quebec, Canada Filed Oct. 12, 1964, Ser. No. 403,068 4 Claims. (Cl. 340-280) The instant invention relates to improvements in a robbery alarm system intended for use in such establishments as banks and the like where money is kept in compartmented cash drawers.

There are presently several such systems in existence and the invention is particularly directed to a system wherein the alarm device is triggered by the thief himself as he picks up a stack of currency money.

It is consequently an object of the invention to provide a robbery alarm system wherein the alarm may be sounded by the thief himself quite unsuspectedly whereby not to antagonize him. The alarm may also be set off by one of the employees if the latter is asked to withdraw the pile of money from the drawer to give it to the robbers, this operation unnoticeably triggering off the alarm.

Another object of the invention lies in providing such an alarm system which is easily constructed, at low cost and is efficient and safe in operation.

The above noted objects may be obtained in a robbery alarm system made according to the invention for use with a cash drawer formed with at least one money receiving compartment and comprising an electrical alarm control circuit mounted beneath the bottom of said compartment and adapted upon energization thereof to cause operation of an alarm device; a light sensitive resistance mounted to extend through said bottom to face upwardly and connected in series in said alarm control circuit; said resistance being adapted upon exposition to light to allow current therethrough and upon being blinded to prevent passage of the current and thus open and deenergize said alarm control circuit; a plate of translucent material over said bottom and over said light sensitive resistance, hiding said resistance from view but allowing light therethrough to affect operation thereof, and a stack of paper money freely disposed over said translucent plate to blind said resistance whereby upon unauthorized removal of said paper money, said resistance becomes exposed to light to thus close and energize said alarm control circuit to cause operation of said alarm device.

A better understanding of the invention will be had by the description that follows of a preferred embodiment of the invention having reference to the appended drawing, wherein:

FIG. 1 is a perspective view of a bank counter provided with a drawer having a robbery alarm system in accordance with the invention;

FIG. 2 is a perspective view, partly shown in crosssection, of a compartment of the drawer of FIG. 1 having a robbery alarm system according to the invention;

FIG. 3 is a vertical cross-sectional view of a protected compartment of the drawer of FIG. 1;

FIG. 4 is an electrical diagram of an alarm system to be mounted in the drawer to be protected.

The invention is used, for instance, in a bank having a series of counters 1 having the usual wickets 3 and provided, inwardly thereof, with a series of cash drawers 5 as illustrated in FIG. 1. Each drawer, as is known, is provided with a plurality of compartments 7 for the reception of stacks of paper currency such as that shown at 9 in FIG. 2. Drawer 5 has a true bottom 11 and a false bottom 13 defining therebetween a housing 15 within which is mounted an electrical alarm control circuit 17, the electrical diagram of which is illustrated in FIG. 4. Control circuit 17 is used to actuate an alarm device 3,300,770 Patented Jan. 24, 1967 19 as is also shown in FIG. 4. However, it should be understood that control circuit 17 may be made to actuate such apparatuses as a radio transmitter, a TV camera, a magnetic or video tape recorder, any type of camera or any other type of anti-theft registering or warning devices. However, for the purpose of this specification and of the claims, the term alarm device will be retained and it is to be understood to mean any of the above-mentioned devices.

The control circuit comprises a light sensitive resistance 21, such as a selenium cell, which is mounted to extend through the false bottom 13 of the drawer 5 and which is connected in series with a transistor amplifier 23, the collector of which is connected to the positive pole of a battery through a coil 25 of an electro-magnetic relay 27 while the other collector is connected to the negative pole of the battery (not shown); the base being connected to one end of the light sensitive resistance 21 while the other end of resistance 21 is connected to the bottom positive pole of the battery through the variable resistance 29. A diode 31 is also provided in parallel with the branch containing light resistance 21 and transistor amplifier 23.

A plate 33 of translucent material, having either a fiat or a knurled surface, preferably plastic, is provided over the false bottom 13 to hide the light sensitive resistance 21 from view while yet permitting light therethrough to affect the light sensitive resistance 21. Preferably, this plate 33 is white and extends completely across and over false bottom 13.

With the above arrangement, it will be understood that Whenever the stack of money 9 is removed from compartment 7, light energizes the light sensitive resistance 21 and closes the control circuit 17 allowing current through transistor amplifier 23 and energizing coil 25 of electromagnetic relay 27 which then operates the alarm device 19. The sensitivity of the light sensitive resistance 21 may beadjusted by allowing more or less current therethrough by adjustment of the variable resistance 29. When resistance 21 is inoperative, as when a stack of money is disposed over translucent plate 33, current is prevented to flow from one pole of the battery of the other by a diode 31.

In the alarm device shown in FIG. 4, a central arm 35 may be made to contact and close a circuit including, for instance, a light to indicate that the alarm device is not operative. As soon as coil 25 is. energized arm 35 is made to move to close the second circuit which actually sounds the alarm while turning off the light. Of course, any other system may be resorted to according to specific conditions or preferences.

Consequently, the invention resides in ensuring that the light sensitive resistance 21 be hidden from view completely so that when an unauthorized person picks up the stack of money thereover, he quite unexpectedly and unsuspectedly triggers an alarm which will bring law enforcing people at the place of the robbery.

Although a specific embodiment of the invention has just been descrided, it will be understood that various modifications may be made thereto without departing from the spirit of the invention, the scope of which is set forth in the appended claims. I

Thus, the invention may be manufactured as an independent unit capable of being mounted in any existing drawer compartment.

We claim:

1. A robbery alarm system, comprising:

(a) a cash drawer formed with at least one paper money-receiving compartment;

(b) an electrical alarm control circuit mounted beneath the bottom of one of said compartments and adapted, upon energization thereof, to cause operation of an alarm device;

() a light sensitive resistance mounted to extend through said bottom to face upwardly and connected in series in said alarm control circuit; said resistance being adapted upon exposition to ambient light when the drawer is opened to allow current therethrough to energize said circuit and upon being blinded to prevent passage of current and thus open and deenergize said alarm control circuit;

(d) a plate of translucent material over said bottom and over said light sensitive resistance to hide said resistance from view, the said plate allowing light therethrough to aifect the operation thereof; and

(e) a stack of paper money freely disposed over said translucent plate to blind said resistance whereby upon unauthorized removal of said paper money, said resistance becomes exposed to light to thus close and energize said alarm control circuit to cause operation of said alarm device.

2. A robbery alarm system, comprising:

(a) a cash drawer formed with at least one paper money-receiving compartment formed with a false bottom above the true bottom; said bottoms defining a housing;

(b) an electrical alarm control circuit mounted in said housing and adapted, upon energization thereof to cause operation of an alarm device;

(0) a light sensitive resistance mounted to extend through said false bottom to face upwardly and connected in series in said alarm control circuit; said resistance being adapted upon exposition to ambient light when the drawer is opened to allow current therethrough to energize said circuit and upon being blinded to prevent passage of current and thus open and deenergize said alarm control circuit;

((1) a plate of translucent material disposed fully over said false bottom and over said light sensitive resistance, hiding said resistance from view but allowing light therethrough to afiect the operation thereof; and

resistance means in said control circuit to adjust the sensitivity of said light sensitive resistance.

4. A robbery alarm unit, comprising:

(a) a substantially fiat rigid member to act as the bottom of a cash drawer compartment;

(b) an electrical alarm control circuit mounted on one face of said member and adapted, upon energization thereof, to cause operation of said alarm device;

(c) a light sensitive resistance mounted to extend through said rigid member with the light sensitive part thereof in the direction of said one face; said resistance adapted upon exposition to ambient light when the drawer is opened to allow current therethrough to energize said circuit and upon being blinded to prevent passage of current and thus open and deenergize said alarm control circuit; and

(d) a plate of translucent material over said light sensitive resistance to hide said resistance from view, the said plate allowing light therethrough to afiect the operation thereof.

References Cited by the Examiner UNITED STATES PATENTS 666,737 1/1910 Coleman. 1,494,656 5/ 1924 Wherland. 1,685,329 9/1928 Lynch. 2,139,703 12/1938 Taylor 340258 2,349,849 5/1944 Deal 340258 2,968,804 1/1961 Bufiington 34028l 3,088,051 4/1963 Scanlon 340258 NEIL C. READ, Primary Examiner.

R. M. GOLDMAN, D. L. TRAFTON,

Assistant Examiners. 

1. A ROBBERY ALARM SYSTEM, COMPRISING: (A) A CASH DRAWER FORMED WITH AT LEAST ONE PAPER MONEY-RECEIVING COMPARTMENT; (B) AN ELECTRICAL ALARM CONTROL CIRCUIT MOUNTED BENEATH THE BOTTOM OF ONE OF SAID COMPARTMENTS AND ADAPTED, UPON ENERGIZATION THEREOF, TO CAUSE OPERATION OF AN ALARM DEVICE; (C) A LIGHT SENSITIVE RESISTANCE MOUNTED TO EXTEND THROUGH SAID BOTTOM TO FACE UPWARDLY AND CONNECTED IN SERIES IN SAID ALARM CONTROL CIRCUIT; SAID RESISTANCE BEING ADAPTED UPON EXPOSITION TO AMBIENT LIGHT WHEN THE DRAWER IS OPENED TO ALLOW CURRENT THERETHROUGH TO ENERGIZE SAID CIRCUIT AND UPON BEING BLINDED TO PREVENT PASSAGE OF CURRENT AND THUS OPEN AND DEENERGIZE SAID ALARM CONTROL CIRCUIT; 